Seven cancer cell strains and 5 sublines of pancreatic carcinoma have been successfully grown in culture. Drug sensitivity studies have been carried out using pancreatic carcinoma (Dangeraux) and lung mesothelioma, VAMT-1. Of all single agents studied, vincristine exhibited the highest inhibitory activity against Dangeraux. This correlates with the in vivo results using the subrenal capsule assay. Two chemotherapeutic combinations, 2'-deoxycoformycin (DCF) plus 8-azaadenosine (8-Aza-Ado) or formycin and 3-deazauridine (3-DAU) plus Ara-C, have been established. In culture, DCF pretreatment for 15 minutes greatly potentiates 8-Aza-Ado or formycin activity against Dangeraux. 3-DAU pretreatment for 2 hours increases inhibitory activity of Ara-C 35 fold. The in vivo studies using ATS-mouse xenografts showed that DCF one hour pretreatment, followed by 8-Aza-Ado significantly reduced the tumor weight to 20 percent of the untreated control while 8-Aza-Ado alone had very little effect. However, DCF in combination with formycin was not as effective. Of nine single agents studied in vitro, vincristine was the most effective against VAMT-1. However, 5-fluorouridine-diphosphate-diglyceride exhibited the highest inhibitory activity among the 5-fluorouracil derivatives (5-FU, 5-FUR, 5-FUdR). 5'-Deoxy- 5 fluorouridine (5'-deoxy-5-FUR) had no activity at all. Since 5'-deoxy-5'FUR cannot be phosphorylated, it appears to indicate that VAMT-1 is deficient in nucleoside phosphorylase which liberates 5-FU from the analog and is phosphorylated via PRPP with the formation of 5-FUMP.